Percussion fuze, particularly for unrifled shells, primarily hollowcharge shells



Jan. 28, 1964 s. D. VON PRZYCHOWSKI ETAL 3, ,337

PERCUSSION F UZE PARTICULARLY FOR UNRIFLED SHELLS. PRIMARILYHOLLOW-CHARGE SHELLS Flled Sept 28, 1959 3 Sheets-Sheet 2 m m m 4 m 4 2m 72 DJ F 8 3 2 F m a a 2 2 M 4 7 J 2 M// 6'. D. van z yclowskl BY JMUZZEI Jan. 28, 1964 s. D. VON PRZYCHOWSKI ETAL 3,119,337

PERCUSSION F UZE, PARTICULARLY FOR UNRIFLED SHELLS, PRIMARILYHOLLOW-CHARGE SHELLS Filed Sept. 28, 1959 5 Sheets-Sheet s United StatesPatent PERCUSSHON FUZE, FAETHZULARLY UNREFLED SHELLEE, FRERMRILY HULLGW-(JHARGE SHELlLfi Siegfried Dunin von Przychnwshi, Eulowstrasse 21,Narnberg; .l'osef Muller, Une'tweg 6, Schrarnherg-Sulgen; HeinrichWirnrner, Mohnwinkel 5, Ruckersdorf; Friedrich Wirth, Etiedlerstrasse255a, Altenfnrt, near Numberg; and Paul Kaiser, Weihergasse 28,Sehramherg, Germany Filed ept. 23, 1959, Ser. No. 842,975 Claims. (Cl.Jim-78} A percussion fuze has already been proposed particularly forunrifled shells comprising a timing mechanism operated by an inertiamember loaded by a feed spring whereby the movement of the inertiamember is braked. This fuze has a locking disc engaging in known mannerbehind the firing pin and carrying a locking finger extending into thepath of the inertia member and coming to bear laterally against theinertia member. The inertia member is at the same time constructed as abrake sleeve with rack teeth in which the driving pinion of the brakingclockwork mechanism engages. When a shell equipped with such apercussion fuze is fired at a low initial speed, the retarding backpressure on the inertia member is not sufficient to overcome theresistance of the braking clockwork on the inertia member with which itis drive-coupled, so that the release does not take place properly.Consequently in the above-mentioned suggestion, the coupling between theinertia member and the braking clockwork is disengaged in that thedriving pinion is shifted out of engagement with the radk teeth of theinertia member. Now braking clockwork mechanisms with disengageablepinion are very sensitive to firing shocks of a certain magnitude andtheir function cannot always be guaranteed; consequently it is proposedin the present case to dispense with the disengageable braking clockworkmechanism and to make the inertia or retarding member in two parts byforming the rack teeth on a braking sleeve which is not subjected to anyretarding backstro e and constructing the retarding member as an inertiasleeve which, for the purpose of braking, is coupled with the sleevebearing the tooth rack. The new percussion fuze is intended primarilyfor hollow-charge shells which are to have a relatively low firing speedand are consequently subjected only to low firing pressures.

Therefore, according to the invention, the inertia or retarding memberbraked during the forward stroke is divided into two members, namely aninert member and a braking member, whereby the braking member performsthe function of holding the locking finger on the pin looking slide. Theinert member is located in front of the braking member and consists ofan inert sleeve, known per se, which telescopically engages in thebraking member, a blocking spring being arranged between the twomembers. The braking member consists of a sleeve provided with a toothedrack which rests on the bottom of the fuze bore and carries the feedspring which presses forward against the end face of the inert sleeve.In the case of backward movement the inert sleeve coupics with thebraking sleeve, in that, for example, an annular spring in the front ofthe braking sleeves snaps into an annular groove in the shank of theinert sleeve. The braking sleeve has on its outer side a longitudinalgroove in which a transverse pin mounted in the fuze body engages andsecures it against turning.

The locking finger on the pin locking slide is made in one piece withthe slide being bent up therefrom.

The fuze is designed so that it Will function in the event of inclinedimpact in that the fuze cap has at its front 3,ll9,353? Patented Jan,28, 1954 end a cylindrical part extending beyond the front face of thefuze body. In the front face of this extension the usual head diaphragmis inserted and the whole extension filled With elastic material. Asheet-metal cone provided with holes is cast in the elastic material sothat its rearwardly directed point bears against the head of the strikerpin and its forwardly directed base bears against the head diaphragm. Asimplification of this fuze cap extension is attained by the fact thatthe fuze cap extension is closed at its front end and completely filledwith elastic material. The striker pin head is of mushroom shape withconical Wall surface and is pressed by the striker pin locking springinto a ring shaped element fitted in the fuze bore and provided with aconical inner surface corresponding to the conical Wall surface of thestriker pin head.

An embodiment of the new percussion fuze is illustrated by way ofexample in the accompanying drawings, in which FIG. 1 is a longitudinalsection through the fuze in safety position, taken in the plane 1-1 ofFIG. 4;

FIG. 2 is a similar view to FIG. 1, after firing and during the shellacceleration, but taken in the plane ll-H of FIG. 4;

FlG. 3 is also :a similar view to FIGS. 1 and 2., but the fuze is inprimed state at the end of the shell acceleration, the section beingtaken in the plane III-Ill of FIG. 4;

FIG. 4 is a cross-section through the fuze taken on line IV-IV of FIG.2;

FIG. 5 is a cross section taken in the plane VV of PEG. 3;

v FlG. 6 is a longitudinal section taken through the fuze head with amodification of the construction shown in FIG. 1;

FIG. 7 shows the retarding mechanism in side elevation and FIG. 8 is alongitudinal section taken in the plane VIII-VIII of FIG. 7.

The fuze body ll), which is encompassed by a cap 11, has an axial bore15 which narrows in steps from the front towards the rear. The axialstriker pin 12 extends through the bore 15 and carries on its front enda mushroom-shaped head 16a tapering conically towards the front of theshell, and at its rear end a firing pin 16 which is inserted in itsshank l2 and provided with a collar bearing against the rear end face ofthe shank of the striker pin. The foremost widest portion 15a of theaxial fuze bore 15 is shut off from its narrower middle portion by aplate 18 which is fixed by a ring 19 pressed into the fuze body 16. Inthe middle portion 15 of the bore a retarding sleeve "22 slides on theshank of the striker pin 12 and is guided by means of a head flange inthe axial fuze bore 15. A braking sleeve 27 is located behind theretarding or inert sleeve 22 in the same portion of the axial fuze bore15. A locking spring 28 is located between the front end face of thebrake sleeve 27 and the rear face of the head flange of the retardingsleeve 22, which spring presses the head of the sleeve 22 against theclosing plate 18 of the middle portion of the fuze bore. The retardingsleeve 22 has a rearwardly extending shank which is of such dimensionthat it can he slipped in telescope fashion into the braking sleeve 27.A feed spring 23a, is arranged in the braking sleeve 27, through whichthe striker pin shank 112 extends, and surrounds the striker pin shank12. This spring 23a bears at its rear end against the bottom of themiddle portion of the fuze bore and at its front end against the rearface of the shank of the retarding sleeve 22 engaging in the brakingsleeve 2-7. An annular spring 29 extending into the front end of thebraking sleeve 27 can snap into an annular groove 33 in the shank of theretarding sleeve 22. A blocking spring 31 is located between the closingplate 18 for the middle portion of the fuze bore and the head 16a of thestriker pin.

The braking sleeve 27 has in its outer wall a longitudinal groove 32 inwhich the inwardly directed end nose 33 of a transverse screw 34,mounted in the fuze body 10, engages and thus secures the braking sleeveagainst turning. The braking sleeve 27 also has on its outer wall rackteeth 35 in which a pinion 24 engages which is rigidly connected with anescapement wheel (FIG. 7). An anchor 26 engages this escapement wheel25. It has an arm a with a solid weight 36. This weighted arm 35a islocated in the central plane of the weight 36 parallel to the axis ofthe fuze.

The fuze striker pin is locked in substantially the same fashion as inthe construction referred to at the outset. The firing pin 16 projectsinto an aperture in the rear end of the shank 10a of the fuze. From theroof of this aperture axially parallel blind bores 37 extend in forwarddirection and retaining pins 20 are pressed into these bores up to aspacer collar 29a formed thereon. A plate 38 is slipped on to these pins20 as far as the spacer collars 20a will allow and is thus securedagainst turning and shifting. Between this point and the roof of theaperture, the striker pin locking slide 21 is mounted rotatable aboutthe pivot 39. This slide has a hook-shaped arm 39a which engages thefiring pin behind its collar and thus prevents its rearward movement.The other arm 40 of the locking slide 21 is bent upwards at right anglesto form a locking finger 23 which in the safety position bears againstthe periphery of the braking sleeve 27. A torsion coil spring 41 isslipped on to the pivot 39, one arm of this spring being hooked on thepin 42 on the slide 21 whereas the other arm is anchored in the plate38. The spring 41 is stressed to such an extent that when the strikerpin locking slide is released it swings into the priming position inwhich the hook arm 39a releases the firing pin.

The new fuze is also designed to respond in the case of inclined impact.For this purpose the fuze cap 11 encompassing the fuze body 10 isextended towards the front and forms a short cylinder 43. A diaphragm 44is beaded in the front end of this cylinder. The hollow space in thecylinder 43 behind the diaphragm 44 is filled with elastic material 45cast therein, for example a material known under the trade name Mipolam.A cone 4-6 made of sheet metal and provided with holes is also cast inthis elastic material 45 so that its apex bears against themushroom-shaped head 16a of the striker pin. This mushroom-shaped headis surrounded by a ring 47 shaped to conform with the mushroom head andpressed into the axial fuze bore from the front.

As can be seen from FIG. 6 the diaphragm is omitted from themodification of the fuze point therein illustrated. Instead thereof thefuze cap surrounding the fuze body is held by means of its thincylindrical extension 43 and closed at its front end. The extension hasno insertion and is entirely filled with elastic material.

The new fuze operates in the following manner:

On a shell being fired the retarding sleeve 22 flies back therebycompressing its locking spring 28. The braking sleeve 27 remainsstationary as in its inoperative position it practically bears at itsrear end. The retarding sleeve 22 slides with its shank into the brakingsleeve and thereby tensions the feed spring 28a in the braking sleeve.When the annular groove 30 in the shank of the retarding sleeve 22 comesopposite the coil spring 29 in the front end of the braking sleeve 27,this spring snaps into the groove thereby rigidly coupling the twosleeves together.

At the end of the shell acceleration, the feed spring 28a in the brakingsleeve commences to operate and pushes the two coupled sleeves forward.This forward movement is braked by the braking clockwork. The rack teethon the braking sleeve 27 in being pressed forward, rotates the pinion 24and consequently also the escapement Wheel 25 whose rotation iscontrolled by the anchor 26.

When the retarding sleeve 22 strikes against the plate 18 it has pulledthe braking sleeve 27 so far that the locking finger 23 is removed fromthe support afforded it by the periphery of the braking sleeve 27. Thestriker pin locking slide 21 is therefore swung in counter-clockwisedirection by its torsion coil spring 41 from FIG. 4 to FIG. 5 so thatits hook arm 39a is swung away from behind the collar 16 of the strikerpin which is consequently released. The fuze is now primed for firing,FIG. 3.

If the shell strikes straight, the diaphragm is knocked back and,through the intermediary of the elastic material in the fuze capextension, transmits the shock to the striker pin head 1611 so that thestriker pin pierces the fuze detonator pellet 13.

If the shell impacts at an incline, the cap extension 43 is laterallydeformed. This deformation is transmitted to the ring 4'7 whosecurvature then becomes oval. Consequently the conical head of thestriker pin is pushed back so that the pin 16 pierces the pellet 13. Inthe event of lateral crushing through inclined impact, it may, however,happen that the diaphragm 44 drops out and the elastic material 45 isforced forward instead of backward. To prevent this, the sheet metalcone 46 is cast in the elastic material and its point assists thestriking back of the striker pin.

In the event of a jolt in transport or due to the shell being dropped,the delay on impact is very short as compared with the longer actingacceleration in the gun barrel. For example, in the event of the shellbeing dropped on its bottom, the retarding sleeve 22 will move slightlybackwards against its blocking spring 28 but not so far that theretarding sleeve 22 and the braking sleeve 27 become coupled. If, on theother hand, the shell is dropped on its nose, the braking sleeve is notmoved forward against the resistance of its blocking spring 28 so farthat the two sleeves 22 and 27 become coupled and the locking finger 23can be released. The fuze therefore remains locked.

We claim:

1. A percussion fuze particularly for unrified shells and primarilyhollow-charge shells, comprising a fuze body having a central boretherein, a striker pin shank slidably mounted in the fuze body, aretarding sleeve slidably mounted on the striker pin shank and in thecentral bore and having a groove in the outside surface thereof, abraking sleeve slidable in the bore and slidably mounted on theretarding sleeve so that the retarding sleeve may telescope into thebraking sleeve upon relative movement of the retarding sleeve on thestriker pin shank, said braking sleeve having a partial groove therein,a holding spring mounted in the partial groove in the braking sleeve andadapted to cooperate with the groove in the retarding sleeve when thelatter telescoeps a sufficient distance into the braking sleeve, a feedspring around the striker pin shank and in the braking sleeve andbearing against the fuze body at one end and against the retardingsleeve at the other end, a slide member pivotally mounted in the fuzebody to hold the striker pin shank in inoperative position, anescapement mechanism in the fuze body connected to the braking sleeve toretard movement thereof, and a locking pin on the slide member abuttingagainst the braking sleeve to keep the slide member in a safety positionand when the shell is fired the acceleration force will telescope theretarding sleeve into the braking sleeve, said sleeves beinginterconnected by engagement of said holding spring with said groove insaid retarding sleeve so that at the end of acceleration of the shellthe two coupled sleeves will be forced forwardly by the feed spring witha retarding action by the escapement mech anism and thus, when thelocking pin abutting against the braking sleeve is freed from the latterthe slide memher will be free from the striker pin shank.

2. Percussion fuze according to claim 1, wherein a fuze cap encases saidfuze body, said cap having a cylindrical extension projecting beyond theforward end of the fuze body, said extension being filled with elasticmaterial and having a percussion diaphragm at the forward end thereof.

3. Percussion fuze according to claim 1, wherein a fuze cap encases saidfuze body, said cap having a cylindrical extension projecting beyond theforward end of the fuze body, said extension being filled with elasticmaterial and having a percussion diaphragm at the forward end thereof,and wherein a perforated sheet metal cone is provided in the elasticmaterial, the apex of said cone directed to the rear bearing against theforward end of the striker pin shank Whereas its base contacts againstthe diaphragm.

4. Percussion fuze according to claim 1, further comprising a conicalhead portion secured to the forward end of the striker pin shank, a ringmember having a corresponding conical inner surface secured in saidcentral bore and a spring biasing said head portion and ring member intoengagement.

5. Percussion fuze according to claim 1, wherein the braking sleeve hason its outer side a longitudinal groove in which a transverse pin in thefuze body engages and prevents the sleeve from turning but permitssliding movement of the braking sleeve.

References Cited in the file of this patent UNITED STATES PATENTS

1. A PERCUSSION FUZE PARTICULARLY FOR UNRIFLED SHELLS AND PRIMARILYHOLLOW-CHARGE SHELLS, COMPRISING A FUZE BODY HAVING A CENTRAL BORETHEREIN, A STRIKER PIN SHANK SLIDABLY MOUNTED IN THE FUZE BODY, ARETARDING SLEEVE SLIDABLY MOUNTED ON THE STRIKER PIN SHANK AND IN THECENTRAL BORE AND HAVING A GROOVE IN THE OUTSIDE SURFACE THEREOF, ABRAKING SLEEVE SLIDABLE IN THE BORE AND SLIDABLY MOUNTED ON THERETARDING SLEEVE SO THAT THE RETARDING SLEEVE MAY TELESCOPE INTO THEBRAKING SLEEVE UPON RELATIVE MOVEMENT OF THE RETARDING SLEEVE ON THESTRIKER PIN SHANK, SAID BRAKING SLEEVE HAVING A PARTIAL GROOVE THEREIN,A HOLDING SPRING MOUNTED IN THE PARTIAL GROOVE IN THE BRAKING SLEEVE ANDADAPTED TO COOPERATE WITH THE GROOVE IN THE RETARDING SLEEVE WHEN THELATTER TELESCOPES A SUFFICIENT DISTANCE INTO THE BRAKING SLEEVE, A FEEDSPRING AROUND THE STRIKER PIN SHANK AND IN THE BRAKING SLEEVE ANDBEARING AGAINST THE FUZE BODY AT ONE END AND AGAINST THE RETARDINGSLEEVE AT THE OTHER END, A SLIDE MEMBER PIVOTALLY MOUNTED IN THE FUZEBODY TO HOLD THE STRIKER PIN SHANK IN INOPERATIVE POSITION, ANESCAPEMENT MECHANISM IN THE FUZE BODY COPNECTED TO THE BRAKING SLEEVE TORETARD MOVEMENT THEREOF, AND A LOCKING PIN ON THE SLIDE MEMBER ABUTTINGAGAINST THE BRAKING SLEEVE TO KEEP THE SLIDE MEMBER IN A SAFETY POSITIONAND WHEN THE SHELL IS FIRED THE ACCELERATION FORCE WILL TELESCOPE THERETARDING SLEEVE INTO THE BRAKING SLEEVE, SAID SLEEVES BEINGINTERCONNECTED BY ENGAGEMENT OF SAID HOLDING SPRING WITH SAID GROOVE INSAID RETARDING SLEEVE SO THAT AT THE END OF ACCELERATION OF THE SHELLTHE TWO COUPLED SLEEVES WILL BE FORCED FORWARDLY BY THE FEED SPRING WITHA RETARDING ACTION BY THE ESCAPEMENT MECHANISM AND THUS, WHEN THELOCKING PIN ABUTTING AGAINST THE BRAKING SLEEVE IS FREED FROM THE LATTERTHE SLIDE MEMBER WILL BE FREE FROM THE STRIKER PIN SHANK.